Method and system for steering an articulated combine

ABSTRACT

Broadly, one aspect of the present invention is an articulated combine having increased on-board grain storage capacity (e.g., 1,200 bushels) and which is composed of a forward unit having an operator&#39;s cab, an engine, a grain harvesting assembly, a grain transfer assembly, and being devoid of an on-board grain bin; and a rearward unit jointedly attached to the forward section and having, steerable and powered wheels, an on-board grain bin for receiving grain from the forward section grain transfer assembly, and a grain off-loading assembly. The grain transfer assembly, joint, and grain off-loading assembly and controls, form other aspects of the present invention.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. Ser. No.09/481,046, filed Jan. 11, 2000, now U.S. Pat. No. 5,125,618, which is adivisional application of U.S. Ser. No. 09/040,985, filed Mar. 18, 1998,now U.S. Pat. No. 6,012,272, the disclosure of which is expresslyincorporated herein by reference.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is cross-referenced to application Ser. No. 08/927,872filed Sep. 11, 1997, the disclosure of which is expressly incorporatedherein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not applicable.

BACKGROUND OF THE INVENTION

The present invention generally relates to combines and moreparticularly to an articulated (jointed) combine which employs, interalia, an improved joint, unloading capability and control, steering, andextremely large grain storage capacity.

A modem agricultural combine typically unloads or transfers clean grainfrom its on-board storage hopper utilizing an auger of fixed lengthwhich swings out in a fixed radius and fixed elevation arc from itsstowed position. The stowed position generally is pointing to the rearof the combine. The auger in turn generally is driven by a mechanicalarrangement of belts, chains, clutch, and gearbox. The unload auger inmost combine: designs swings out to the operator's left. The augerlength generally is limited by the practical distance that it can extendbeyond the rear of the combine in its stowed position without creating aserious maneuvering hazard.

As the size of on-board storage hoppers and capacity of combines hasincreased, the time required to maneuver the machine next to the grainreceiving wagon or truck and the grain transfer time have become a majorcomponent of the total harvesting time. Conventional combines have agrain hopper capacity of 250 to 300 bushels and unload auger capacitiesof 1.9 to 2.6 bushels per second.

The unload time of the hopper typically is about 2 to 3 minutes with theunload auger running at maximum speed and 1 to 2 minutes are taken tomaneuver the combine into the optimum unload position next to the truckor wagon. Re-positioning the combine and running the auger at less thanmaximum speed are often encountered when topping off the truck or wagonwhich is receiving the grain. As modern combine harvesting capacitiesapproach 3,000 bushes per hour, the unload cycle must be repeated every8 to 10 minutes. Therefore, the total unload time or non-harvesting timeis a significant reduction of total grain harvesting productivity.

This productivity loss can be countered by a second operator utilizing atractor and grain cart following the combine back and forth through thefield to unload the on-board combine storage hopper without stopping theharvesting process. Alternatively, a combine with an integrated graincart, as disclosed in application Ser. No. 08/927872, cited above, canbe utilized to reduce the number of unload cycles and at least doublethe rate at which grain is discharged to the receiving vehicle.

Unloading combines into semi-trailer road trucks has become theprevalent practice as opposed to field wagons which were utilized in thepast. These road trucks typically are parked at the side of the road andnot in the field where the combine is operating. This necessary practicealmost always creates an elevational difference between the twovehicles. These road trucks themselves also have widely varying heights.These two conditions create a big variation in the optimum elevation ofthe discharge point of the combine unloading system. Combinemanufacturers have attempted to address this problem with ever longeraugers and higher fixed swing out arcs. There are, however, limits toboth. This fixed point discharge point frequently ends up too high, toolow, too far from the combine, or too close to the combine for optimumtruck loading conditions. Such conditions require repositioning thewhile combine with respect to the vehicle it is loading.

Existing combine unloading systems can unload from one side of themachine only. This frequently requires 180° turns by the combine toposition it on the proper side to unload the grain into the road truck.It also means that the combine can be unloaded into a moving grain cartwhen traveling only in one direction through the field since access toone side of the combine is virtually always blocked by unharvested crop.

When topping off or completely filling the truck or wagon, it isnecessary for the operator to inch the combine forward or backwardduring the process. In addition to being cumbersome, the combine must bepositioned close to perfectly parallel to the receiving vehicle or astop and reposition is necessary. The lack of parallelism frequentlycannot be solved by moving the auger through its fixed arc.

An agricultural combine has multiple steering requirements. Precisecontrol is needed as the row harvesting units such as a cornhead, areguided through the rows of grain. When the end of the field is reached,a tight turning radius is needed to proceed back across the field inorder to harvest the crop immediately adjacent to the just-completedrows or round. Concomitant with its field performance, this largevehicle also must be controlled on the roadway at speeds of around 20mph and around tight corners. Another steering associated problem is toturn multiple axle, heavily-loaded bogies with large tires in a tightradius while minimizing sliding the tires in the horizontal directionwhich places high stresses in the suspension, piles up dirt in thefield, and causes excessive tire wear.

An early attempt at an articulated combine is reported in U.S. Pat. No.4,317,326. The design capacity is stated to be around 360 bushels. Itsunloading mechanism is limited to one side of the combine and steeringis accomplished only by articulation steering cylinders. To date, noarticulated combine is commercial. Clearly, there is a need for a moreflexible, faster, and convenient combine which overcomes these and otherproblems such as those set forth above.

BRIEF SUMMARY OF THE INVENTION

The present invention is addressed to solving the problems detailedabove by providing an articulated (jointed) combine which employs, interalia, an improved joint, unloading capability and control, transfer ofgrain from a forward unit to a grain bin on a rearward unit, andextremely large grain storage capacity. Broadly, then, one aspect of thepresent invention is a combine, preferably articulated, having increasedon-board grain storage capacity and which is composed of a forward unithaving an operator's cab, an engine, a grain harvesting assembly, agrain transfer assembly, and being devoid of an on-board grain bin; anda rearward unit jointedly attached to the forward section and having,steerable and powered wheels, an on-board grain bin for receiving grainfrom the forward section grain transfer assembly, and a grainoff-loading assembly.

Another aspect of the present invention is directed to a joint for apowered articulated vehicle, such as a combine for joining a forwardunit to a rearward unit. The joint includes an upper frame membercarried by the forward unit and having a recess on its lower side and alower frame member carried by the forward unit, having a recess on itsupper side, and being spaced-apart vertically below the upper framemember so that the recesses are in vertical registration. The jointfurther includes a shaft carried by the rearward unit and a bearingretainer assembly carried by the end of the shaft and disposed betweenthe recesses. The bearing assembly includes an outer annulus surmountingan inner hub which hub is connected to the shaft with thrust bearingsinserted between the annulus and said hub, whereby the inner hubco-rotates with shaft with respect to the outer annulus. The bearingassembly also includes a pair of nibs carried by the outer annulus whichnibs reside in the upper and lower recesses and which nibs areassociated with tapered roller bearings so that the outer annulusco-twists with the shaft respect to the forward unit. Uniquely, thejoint is stiff in the longitudinal axis formed along the forward unitframe members and the rear unit shaft.

A further aspect of the present invention is an improved articulatedcombine of a forward unit and rearward unit which connected by a jointwherein the improvement is directed to transferring clean grain from theforward unit to the rearward unit. Such improved combine is composed ofa rearward unit which has a forward and the forward unit has a back,both of which conform in shape to each other and both of which arecurved to match the radius of articulation of the combine. The rearwardunit forward has a horizontal slot in it. The grain transfer assemblyhas an elongate discharge end which fits into the rearward unit forwardhorizontal slot for providing grain transfer capability to the on-boardrearward unit grain bin while the forward and rearward units are beingturned about the joint interconnecting the forward and rearward units.

Yet another aspect of the present invention is an unload assembly forunloading clean grain from a combine grain bin and which is composed ofa telescoping grain movement assembly composed of a proximal grain moverand a distal grain mover. The proximal grain mover is pivotally attachedto the grain bin for movement to either side of the grain bin and formovement vertically. The distal grain mover is in telescoping attachmentwith the proximal grain mover and from which clean grain is dischargedfrom the unload assembly.

Advantages of the present invention include a combine design, preferablyan articulated combine, which enables grain storage capacity of between500 and 1,000 bushels or more. Another advantage is an articulatedcombine which can unload clean grain to either side and which iscontrolled by a unique control system. A further advantage is a uniquesteering system for an articulated combine. These and other advantageswill be readily apparent to those skilled in this art.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and objects of the presentinvention, reference should be had to the following detailed descriptiontaken in connection with the accompanying drawings in which:

FIG. 1 is a side elevational view of the novel combine (or harvester)with extra large storage capacity, novel joint, clean grain transferability, and unloading capacity;

FIG. 2 is an overhead view of the grain trailer depicted in FIG. 1;

FIG. 3 is a sectional view taken along line 3—3 of FIG. 1;

FIG. 4 is a sectional view taken along line 4—4 of FIG. 3;

FIG. 5 is a single axle rear unit version of the combine depicted inFIG. 1;

FIG. 6 is a track driven rear unit version of the combine depicted inFIG. 1;

FIG. 7 is a side-elevational cut-away view of the novel clean graintransfer assembly depicted in FIG. 1;

FIG. 8 is a partial side elevational view of a joystick used to controlthe clean grain transfer assembly depicted in FIG. 7;

FIG. 9 is a top view of the joystick shown in FIG. 8;

FIG. 10 is a schematic of the hydraulic vertical control for the cleangrain transfer assembly of FIG. 7;

FIG. 11 is a schematic of the hydraulic swing control for the cleangrain transfer assembly of FIG. 7;

FIG. 12 is a schematic of the hydraulic telescoping control for theclean grain transfer assembly of FIG. 7;

FIG. 13 is a schematic of the hydraulic speed control for the cleangrain transfer assembly of FIG. 7;

FIG. 14 is a schematic of the hydraulic steering system for the novelarticulated combine;

FIG. 15 is an overhead view of a the novel combine with an alternativeconveyor assembly for feeding grain from the grain bin to the novelclean grain transfer assembly;

FIG. 16 is a side-elevational cut-away view of the alternative cleangrain transfer assembly depicted in FIG. 15; and

FIG. 17 is a view along line 17—17 of FIG. 16.

The drawings will be described in detail below.

DETAILED DESCRIPTION OF THE INVENTION

The present invention addresses problems associated with modern farmingcombines by providing a harvester which can unload readily on eitherside and to virtually any height road truck. The harvester alsoincreases the harvested grain carrying capacity from about 200-300bushels in conventional combines to about 500-1,200 bushels utilizingthe rearward-only grain bin because the rearward unit has more spacethan there is over the front axle. This is important because thecapacity of a typical road semi-trailer is 1,000 bushels. This meansthat the novel combine can fill an entire road truck from its on-boardgrain bin in a single unloading. Moreover, the unique unloading systempermits unloading of clean grain from the rearward grain cart on eitherside of the combine. Such increased grain storage capacity is possiblebecause locating the grain bin on the rearward unit permits a much lowercenter of gravity to be designed into the rearward unit.

In order to ensure that the extra weight can be easily maneuvered by thenovel harvester, the rearward unit has powered and steerable wheels. Thetypical grain bin located on the forward unit now has been eliminated bydint of the rearward unit on-board storage bin. The forward unit nowonly needs to have an operator's cab, an engine, a harvesting assembly(including grain cleaning), and a clean grain transfer assembly fortransferring clean grain from the forward unit to the rearward cartgrain bin. Finally, the forward and rearward units are interconnected bya unique two-axis joint. Chaff from the harvesting assembly isdischarged downwardly and to the side of the two-axis joint which needsto be rounded in design so that the chaff does not build up on anyhorizontal surfaces.

Steering problems associated with heavily-loaded, large tired bogies isinventionally solved by a compound or combination steering system whichutilizes steerable wheels on the rearward bogey or unit and conventionalsteering cylinders at the articulated joint. Compound steering systemshave been used in agricultural tractors to provide for both tightturning radiuses and precise row steering. An example of such a systemis disclosed in U.S. Pat. No. 4,802,545 which proposes a 4-wheel drivetractor equipped with both an articulation joint and a pivotable frontaxle in a wagon-wheel configuration. The pivoting front axle is used forprecise row steering and articulation is added for tight radius turns.

The present invention utilizes powered and steerable rearward units tosupport the harvested grain, as first disclosed in application Ser. No.08/927,872 (cited above). The steerable and powered rear axles alsominimize the horizontal sliding problem by providing a coordinatedturning radius of multiple axle configurations. The steerable rearwheels are used for relatively small steering corrections and forprecise row following while harvesting The rotation of the rear wheelsteering wheels of approximately 15° to 20°, then, is augmented byconventional steering cylinders at the articulation joint to accomplishtight radius turns. Limiting the rear wheel turning in degrees alsominimizes their intrusion into space needed to maximize grain carryingcapacity.

Although more elaborate control systems may be utilized, the compoundsteering disclosed herein may be safely implemented using two ratherconventional steering valves or a multiple port valve actuated by theoperator steering wheel located in the combine cab. When the operatormoves the steering wheel a small increment, the first valve or portdirects hydraulic fluid to the steering cylinder at the rear axles. Ifthe operator continues turning the steering wheel in the same direction,hydraulic fluid or oil will be directed further to the rear axlesteering cylinders until they reach a maximum travel and articulationbegins by the valve now directing oil to the articulation cylinders.When the operator calls for the vehicle to return to a straight aheaddirection, the articulation cylinders return to their balanced, equalextension, home position. The rear wheel steering cylinders then receiveoil flow from the steering valves in the reverse direction to move therear wheels to their straight ahead home position. At all relevanttimes, both the rearward unit wheel steering cylinders and thearticulation cylinders are held in position by check valves until thesteering valve directs oil flow to them which causes the check valves toopen. The check valves prevent external forces from causing the combineto drift when the operator is not calling for a change in direction.Alternatively, the operator can override these controls and manuallyarticulate the novel combine.

Referring initially to FIGS. 1 and 2, innovative combine 10 generallyincludes forward unit 12 and rearward unit 14. Forward unit 10 is seento include cab 15 in which the operator is seated, cornhead or smallgrainhead 16, engine compartment 18 (fan discharge shown in thedrawings), and powered non-steerable wheel pair 20. Rearward unit 14 isinterconnected to forward unit 12 via joint assembly 22 and clean grainis transferred from forward unit 12 to rearward unit 14 via graincleaning and transfer assembly 24 seen in the cut-away view. Rearwardunit 14 is seen to include clean grain unloading system 26 in its storedposition and in phantom in a raised position, grain bin 28, and poweredand steerable wheel pairs 30 and 32. Use of a dual axle configuration ofpowered and steerable wheels supporting grain bin 28 on rearward unit 14contributes to the capability of grain bin 28 holding upwards to 1,000bushels of grain or more. Providing the grain bin capacity only onrearward unit 14 translates into a lower center of gravity for grain bin28 which also enables such higher storage capacity and provides moreeven weight distribution per axle.

As seen in FIG. 2, clean grain from forward unit 12 is transferred tograin bin 28 via grain transfer assembly 24 which includes a generallyhorizontal transfer device (e.g., auger, bucket conveyor, cleatedconveyor, or the like) which extends into a slot in the side of grainbin 28 which confronts forward unit 12. Note should be made of thearcuate configuration of the rear of forward unit 12 and the front ofrearward unit 14 and that these arcuate; configurations conform to eachother. Moreover, the arc of such configuration is based or, thearticulation radius of curvature. Such conforming arcuate design permitsforward unit 12 to be turned either to the right or to the left, asshown in phantom in FIG. 2.

Slot 34 in the front wall of grain storage bin 28 permits horizontaltransfer device 36 to continue to dump grain into bin 28 as forward unit12 is turned from side to side, also as shown in phantom in FIG. 2. Slot34 is associated with a “slide” which commences at the top of bin 28 andslants downwardly to meet with hopper fill auger 38 (often called a“bubbler” auger). Such slant ensures that all grain transferred into bin28 will be directed to the bottom of bubbler auger 38 for distributionof clean grain within bin 28. Transfer device 36, suitably a conveyorcould be fixed to forward unit 12 with slot 34 taking up its movement ascombine 10 is steered left or right. In this regard, the originationpoint of transfer device 36 does not need to be located at thecenterline of forward unit 12, but can be located to the side of thejoint and still feed grain to grain bin 28. Additional flexibility,then, is afforded the combine designer because of the ability to locatethe feed end of transfer device 36 to one side of the other of thecenterline of forward unit 12.

Alternatively, conveyor 36 could be pivotally mounted to forward unit 12and slot 34 would not need to be substantially the entire width of grainbin 28 as steering of combine 10 would be taken up by such pivotmounting. In such embodiment, slot 34 need only be an opening throughwhich grain is transferred into bin 28 via transfer device 36. Also,conveyor 36 would need to be located over the joint axis (centerline offorward unit 12) when pivotally mounted to forward unit 12. Conveyor 36even could be biased to return to a central station once a turn wascompleted.

Once the clean grain has been transferred into bin 28, it is distributedwithin grain bin 28 by hopper fill auger 38, which extends from a frontcorner of bin 28 to around the upper mid-section of bin 28. Grain isunloaded from bin 28 commencing with unload or drag augers 40 and 42which are located along the bottom of bin 28 and which vertical auger 44powered by motor 45 (seen in phantom in FIG. 2 and in cross-section inFIG. 7) which suitable also could be a bucket conveyor or other suitabledevice for transporting grain vertically to clean grain unloading system26.

Referring to FIG. 7, a cross-sectional view of the grain unloadingsystem of the present invention is shown in detail. Clean grain housedin bin 28 is dragged to vertical auger 28 by augers 40 and 42. Auger 44could, of course, be replaced by a bucket elevator or other convenientmechanism for vertically transporting clean grain from within bin 28 upthe level of unloading system 26. Motor 88, which conveniently is ahydraulic motor, motivates unloading system 26 to rotate about thelongitudinal axis of auger assembly 44 in either direction in order tounload the grain into a grain cart, road truck, or other storagelocation. Unique is the ability to move unloading system 26 to eitherside of combine 10.

Shroud 90 confines the grain for dumping onto conveyor system 92 whichitself is shrouded because the conveyor of conveyor system 92 rotates inthe clockwise direction. Again, conveyor system 92 conveniently could bereplaced with an auger, a chain with, paddles, or other grain movingdevice. As shown, conveyor system 92 employs upstanding cleats in orderto urge the grain along the desired path.

The vertical elevation of unloading system 26 is determined by actuator94 which can be a rod and piston assembly as shown connecting verticalauger assembly 44 to conveyor system 92. Power again conveniently issupplied by a hydraulic motor; although, other power means may beemployed as is necessary, desirable, or convenient in conventionalfashion.

In order to be able to unload grain a given distance from combine 10,telescoping conveyor assembly 96, which preferably rotates in thecounter-clockwise direction, telescopes from conveyor assembly 92. Whilea rack and pinion assembly powered by a motor (not shown) is evident inthe drawings, a rod and cylinder assembly or other mechanism couldprovide telescoping movement of conveyor assembly 96. For that matterpower, to move the conveyors in conveyor assemblies 92 and 96, hydraulicmotors (not shown) preferably are provided. Preferably, conveyor system96 rotates in the opposite direction of conveyor system 92; although,such opposite direction movement of conveyors 92 and 96 is not necessaryfor the unique unloading system of the present invention. Ultimately,clean grain exits conveyor assembly 96 via spout 98. With the ability torotate unloading system 26 to either side of combine 10, to control thevertical elevation of unloading system 26, inching control, and toextend the length of unloading system 26, the novel grain unloadingsystem has the ability and capability to unload grain in trucks parkedat a different elevation than is combine 10, parked a variety ofdistances from combine 10, and parked on either side of combine 10.Depending upon the type of grain conveyance utilized, conveyor assembly96 could be open or closed at its top.

With respect to operation of clean grain unloading system 26, referenceis made to FIGS. 8 and 9 which show a unique joystick control systemwhich controls such unloading system. Initially, joystick 100 is fittedwith finger toggle switches 102, 104, 106, and button 108. Toggle switch102 is activated by the operator's fingers and causes unloading system26 to move vertically up and down. Switch 104 conveniently is thumbactivated and is an on-off switch for unloading system 26. Switch 106 isa combine inching switch, that is, it causes combine 10 to move slowlyforward or backward to place spout 98 exactly where the operatordesires. Such slow movement is known as “inching” in this field. Button108 is a “home” button which means that unloading system 26 is returnedto its stored position as shown in FIG. 1, for example.

Another capability of joystick 100 is that it can move forward,backward, and laterally left and right. These movements cause unloadingsystem 26 to extend (say, forward movement of joystick 100), retract(backward movement), swing to the left (left movement), and swing to theright (right movement). Finally, joystick 100 is rotatable to controlthe speed of the conveyors making up unloading system 26.

Joystick 100 accomplishes the described movements of unloading system 26by signaling electrohydraulic valves with a signal sent to manuallyadjustable flow control valves for, say, movement of unloading system 26up/down, left/right, in/out, and home. Joystick 100 signals aproportional servo valve for on/off and conveyor speed (e.g., activatesa linear electric servo that moves a pump swash plate). Joystick 100signals the propulsion system of combine 10 in order to inch the combineforward or reverse by by-passing the normal operator speed control ofthe vehicle. It should be obvious that the novel combine takes advantageof the hydraulic system already in place in conventional combines andextends their use in order to desirably power the unloading system 26and wheel pairs 30 and 32. Other power means, of course, could beemployed; however, hydraulic power tends to be more reliable.

Implementation of such joystick movements of unloading system 26 isdisplayed in FIGS. 10-13. Referring initially to FIG. 10, lines 110 and112 are connected to a source of voltage (say, 12 volts supplied by thecombine). Contacts 114 and 116 are joystick 100 contacts for raising andlowering, respectively, unloading system 26. Ground 117 is provided inconventional fashion. Upon closure of one of joystick contacts 114 or116, bi-directional valve with adjustable flow 118 is fed hydraulicfluid at, say, 2,000 psi from a hydraulic pump which feeds rod andcylinder assembly 94 via lines 120 and 122 with oil returned toreservoir 124 via line 126. Assembly 94, then, raises and lowersunloading system 26 (conveyor systems 92 and 96).

Referring to FIG. 11, lines 128 and 130 run to joystick contacts 132 and134 which actuate bi-directional valve with adjustable flow and float136 which actuates motor 88 for swinging unloading system 26 either leftor right. Ground 138 and return line 140 to reservoir 124 are providedin conventional fashion. A rod and cylinder or other means could besubstituted for motor 88.

Referring to FIG. 12, lines 140 and 142 run to joystick contacts 144 and146 which actuate bi-directional two flow valve (slow/fast speed) 148which actuates motor 150 for extending unloading system 26 in and out(telescopingly extending unloading system 26). Ground 150 and returnline 154 to reservoir 124 are conventionally provided. A rod andcylinder or other means could be substituted for motor 150.

Referring to FIG. 13, the unload system speed control is shown.Specifically, line 156 has on/off switch 108 which activates linearservo unit 158. Line 160 at, say, 2 volts, runs to joystick 100potentiometer (actuated by rotation of joystick 100) which in turn runsto linear servo unit 158. Linear servo unit 158 controls variabledisplacement pump 164 which runs from, say, 0-2,000 psi. In turn, pump164 pumps oil through flow divider 166 which divides the hydraulic flowto motor 168 via line 167 which runs drag augers 40 and 42 andupstanding auger 44 (the speed of drag augers 40 and 42 needs to becontrolled and matched with the speed of auger 44 since these dragaugers feed grain to auger 44) with the oil then returning via line 170to reservoir 124. At this point in the description it should be notedthat reservoir 124 is notated on the drawings as the reservoir for allhydraulic fluid circuits. Obviously, additional reservoirs could be usedas is necessary, desirable, or convenient.

Next, hydraulic fluid or oil from flow divider 166 flows via line 172into second flow divider 174 which splits the hydraulic fluid flowbetween motor 176 via line 178 which motor runs conveyor assembly 92 andmotor 180 via line 182 which motor runs outer conveyor assembly 96. Flowdivider 174 permits more flow to pass into line 182 than into line 178,say, 55%/45%, in order for outer conveyor assembly 96 to run at a fasterrate, say, 10% faster, than conveyor assembly 92 in order to preventplugging of conveyor assembly 96. Oil from motor 176 returns via line184 to reservoir 124 while oil from motor 180 returns to reservoir 124via line 186.

An alternative clean grain unloading system is presented in FIGS. 15-17.Specifically, auger 44 has been replaced with bucket conveyor assembly286 which is powered by hydraulic motor 288 which is located at the topsprocket of assembly 286. Rotation of assembly 286 and raising/loweringof conveyor assembly 26 is accomplished by cylinder assemblies 292 and294. Channel ring 287 which is held in position by bars 296, 297, and298. Riding within channel ring 287 are four wheel assemblies 289 a-dwhich are connected to bucket conveyor assembly 286. Thus, as the rod ofcylinder assembly 292 extends/retracts, conveyor assembly 286 rotateswithin channel ring 287.

Cylinder 294 is attached at one end to the channel ring 287 via a wheeland at its other end to conveyor assembly 286. As conveyor assembly 286rotates (by cylinder assembly 292), conveyor assembly 294 also rotatesby dint of its wheeled attachment to channel ring 287. Cylinder 294causes conveyor assembly 286 to tilt as its rod extends/retracts andsuch tilting can be accomplished regardless of the rotational positionof assembly 286. Because of the moment created when conveyor assembly286 tilts, it is disposed within circular channel 290 about its lowerend. Wheel assemblies 300 and 302 are attached at one end to conveyorassembly 286 with their wheeled opposite ends disposed in the innerchannel formed within ring 290. As cylinder 294 causes conveyor assembly286 to rotate, the wheels of assemblies 300/302 become pivot points forthe lower end of assembly 286 to also rotate.

Next, it will observed that inner conveyor assembly has been replaced(compared to the conveyor assembly in FIG. 7) with an auger housedwithin a shell for conveying grain from bucket conveyor 286 totelescoping cleated conveyor 96. Motor 306 effects rotation of auger304. Finally, it also is possible to string guy wires from combine 10,say at conveyor assembly 286 (or 44 in FIG. 7) to support conveyorassembly 96, 92, and/or 304, as is necessary, desirable, or convenient.For that matter, other means of supporting the weight of telescopingassembly 26 may be designed and implemented depending upon needs. Forexample, conveyor assembly 96 may be made of aluminum in order to reduceits weight.

Regarding to the novel two-axis joint of the present invention, uniqueto joint 22 is that it is a “single point” joint. That is, joint 22 isdesigned to be only about a foot or so high. No other structuralconnection between forward unit 12 and rearward unit 14 is required bydint of the design of joint 22. That is not to say that other structuralconnection cannot be made between forward unit 12 and rearward unit 14,but that such other structural connection is unnecessary. In fact, it isa positive advantage that no other structural interconnection is neededbetween the two units because the combine designer has greaterflexibility in locating equipment, lines, feeders, etc. because of thesingle point joint design disclosed herein.

Referring to FIGS. 3 and 4 which illustrate joint 22, initially,however, it will be observed that a pair of steering cylinders, 46 and48, are seen in FIG. 2 to connect forward unit 12 to rearward unit 14 ofarticulated combine 10. Such steering cylinders are conventionally usedto assist in the steering of articulated vehicles and are provided herefor such steering use in the present articulated combine design. Now,with respect to the two-axis joint, pipe 50 is attached to rearward unit14 at one end and is constructed as a round pipe or structural tubebecause it is in the chaff/straw flow path from grain cleaning andtransfer assembly 24. Shaft 52 extends from pipe 50 towards forward unit12 and is inserted into bearing retainer assembly 60 which is insertedbetween upper frame member 54 and lower frame member 56. These framemembers 54 and 56 are bolted to forward unit 12 via bolts 58 a-d,although other attachment means certainly can be envisioned. Each framemember 54 and 56 has an inner recess which confront each other and intowhich is inserted bearing retainer assembly 60.

Bearing retainer assembly 60 has a pair of nibs or ears which fit intoframe member 54 and 56 recesses and which ride on tapered rollerbearings 62 a-62 d to provide sideways movement to units 12 and 14 viashaft 50. Such sideways movement permits combine 10 to be steered. Ahole penetrates through bearing retainer assembly 60 into which atapered threaded end of shaft 52 fits and is secured via nut 64. Now,thrust bearings 66 and 68 fit into recesses which adjoin the holethrough bearing retainer assembly 60 and which thrust bearings permitshaft 52 to rotate and which, thus, enable units 12 and 14 to rotatewith respect to each other. Such rotation permits units 12 and 14 totraverse uneven terrain during harvesting or other movement of combine10. Note, however, that pipe 50 and shaft 52 are not permitted to movein a vertical direction due to the unique construction of joint assembly22. Thus, a unique dual axis joint has been disclosed.

Harvester 70 shown in FIG. 5 is a 500 bushel version of the novelarticulated harvester because it has a single axle for rearward unit 72.Wheel pair 74 again is powered and optionally steerable (all wheel pairsmay be designed to be oscillating with a walking beam or non-oscillatingas is necessary, desirable, or convenient in conventional fashion,)while wheel pair 76 for forward unit 78 is powered and non-steerable.Steering may be accomplished only by steering cylinders 46 and 48 inthis combine embodiment. The operation of the joint axis, grain bin, andunload conveyor system remains the same for this embodiment of thepresent invention.

FIG. 6 shows yet another embodiment of the present invention wherecombine 80 is provided track driving system 82 for rearward unit 84.Forward unit 86 remains the same as described with respect to combines10 and 70. A unique steering system for track driven combine 80 isdisclosed in applicant's application Ser. No. 09/210,331, filed Dec. 11,1998 (attorneys docket no. DIL 2-003).

Steering the novel articulated combine, both in the field and onroadways, presents some unique problems because of the articulationjoint connecting forward unit 12 and rearward unit 14. One steeringsystem for accomplishing this task is set forth in FIG. 14. The combineoperator in cab 15 steers combine 10 via steering wheel 188 which isconnected to valves 190 and 192, which optionally could be replaced witha single multi-port valve. Valves 190 and 192 are fed hydraulic fluidvia line 194 at, say, 2,000 psi and are also connected to reservoir 124via lines 196 and 198, respectively. Since steering is accomplished byboth articulation steering cylinders 46 and 48, and by a pair ofsteering cylinders, 200 and 202 attached to wheel pair 30 and by anadditional pair of steering cylinders associated with wheel pair 32 (notshown in the drawings). Since steering is initiated by wheel pairs 30/32first turning, hydraulic fluid from valves 190/192 flow via lines 204and 206 to transition servo valve 208 which also is fitted with oilreturn lines 210 and 212 to valves 190/192, respectively and line 214which runs to tank 216 (as stated above, hydraulic fluid or oil tanks124 and 216 may be the same or different tanks).

Transition servo valve 208 operates by first passing hydraulic fluidthrough line 218, to check valve 220 which also has return line 222 totransition servo valve 208. Check valve 220 is associated with steeringcylinders 200/202 via distributor line 224. Cylinders 200/202 havereturn distributor line 226 to check valve 220. Check valve 220 holdsthe pressure on cylinders 200/202 in order that inadvertent bumps andother obstacles do not cause wheel pair 30 (or 32) to deviate from theirset course unexpectedly. Now, it is anticipated that wheel pairs 30/32will only need to turn a slight bit, say 10° to 20°. When wheel positionsensor 228 senses that maximum travel of cylinders 200/202 isapproaching, oil in transition servo valve 208 commences to be divertedslowly into line 230 which runs to check valve 232 which also is fittedwith return line 234. Once full stroke of cylinders 200/202 is reached,all of the hydraulic fluid is shunted to line 230 and check valve 220holds cylinders 200/202 in position.

Check valve 232 is associated with steering cylinders 46/48 viadistributor line 226 and return distributor line 238. Steering cylinders46/48 now articulate combine 10 to effect full turning of it. When theturn is completed, the system works in reverse, that is steeringcylinders 48/48 and returned to their home position first followed bywheel cylinders 200/202. The flow through transition servo valve 208 asdescribed is intended to make the turning transition between cylinders200/202 and 46148 as smooth as possible.

Now, operator knows the precise position of wheel pairs 30/32 by meansof sensor 228 and of articulation steering cylinders 46/48 (and hencethe relative position of forward unit 12 and rearward unit 14 aboutjoint assembly 22) by means of sensor 240. Sensors 228/240 areconnected, respectively, by lines 242 and 244 to steering controller 246which publishes their respective positions to the operator via displays248 and 250 which are connected to controller 246 by lines 252 and 254,respectively. Controller 246 is connected by line 256 to a source ofpower (say, the 12 v battery of combine 10) and is actuated by switch258 which determines whether a manual or automatic articulating mode isestablished, switches 260 and 262 which are left/right rocker switches.These switches also are located in cab 15 for the operator's use. Inturn controller 246 actuates transition servo valve 208 and manualarticulate valve 264 by lines 266 and 268, respectively.

Manual articulate servo valve 264 is energized by line 270 which isconnected to, say, 2,000 psi hydraulic fluid with line 274 returning thefluid to reservoir 216. Manual articulate servo valve 264 is connectedby lines 276 and 278 to check valve 280 which in turn is connected bylines 282 and 284 to check valve 232. Manual articulate servo valve 264permits the combine operator to manually cause operation of articulationsteering cylinders 46/48 as an override to steering controllers 246 andtransition servo valve 208 Thus, the operator can permit the compoundsteering system to operate fully automatically or the operator canoverride such system and manually articulate combine 10 while steeringwheel 188 controls steering wheel pairs 30/32. This gives the operatorthe maximum flexibility in steering combine 10 in expected as well asunexpected conditions.

It will be appreciated that the foregoing description is illustrative ofhow the present invention can be practiced, but it should not beconstrued as limiting the present invention. Finally, all citationsreferred to herein are expressly incorporated herein by reference.

What is claimed is:
 1. A method for steering an articulated combine of aforward unit having a pair of powered non-steerable wheels and arearward unit which has at least one pair of powered steerable wheels,wherein a pair of steering articulation cylinders connect said forwardand rearward units, which comprises the following steps: (a) initiatinga turn of said combine which causes said rearward unit wheel pair tocommence turning of said combine; followed by (b) when said rearwardunit wheel pair approaches its maximum turn, initiating movement of saidsteering articulation cylinders to complete said turn.
 2. The steeringmethod of claim 1, wherein said steps are reversed in order tostraighten out said vehicle from its turn.
 3. A system for steering anarticulated combine of a forward unit having a pair of powerednon-steerable wheels and a rearward unit which has at least one pair ofpowered steerable wheels, wherein a pair of steering articulationcylinders are connected between forward and rearward units, and a jointwhich interconnects said units, which comprises: (a) a steering wheelwhich initially activates said rearward unit wheel pair to commenceturning of said combine; (b) sensors associated with said rearward wheelpair and with said joint; and (c) a controller associated with saidsensors and which commences activation of said steering articulationcylinder pair to complete a turn when said rearward wheel pair sensorindicates that said rearward wheel pair is approaching maximum turn. 4.The system of claim 3, wherein to straighten out said combine, saidcontroller causing said steering articulation cylinder pair to return toa straight position followed by said controller causing said rearwardunit wheel pair to straighten out.
 5. The system of claim 3, whereinsaid steering wheel activates a transition servo valve which activates apair hydraulic cylinders associated with said rearward unit wheel pairand which also activates said steering articulation cylinder pair. 6.The system of claim 5, wherein check valves are associated with saidrearward unit wheel pair hydraulic cylinders and with said steeringarticulation cylinder pair.
 7. The system of claim 3, wherein a manualarticulate servo valve is activatable by an operator of the combine toactivate said steering articulation cylinder pair.
 8. The system ofclaim 6, wherein said controller publishes to an operator of the combinea display of the position of said steering articulation cylinder pairand of said rearward unit wheel pair.